Combined switch and fastener



June 9, 1953l J. w. I ILEY COMBINED SWITCH AND FASTENER ssheets-sheet 1Filed May 22, 1951 mxo Jrz

VMMPWWI flll June 9, 1953 J. w. I ILEY COMBINED SWITCH AND FASTENER 3Sheets-Sheet 2 Filed May 22, 1951 June 9, 1953 J. w. LILEY 2,641,662

COMBINED SWITCH AND FASTENER Filed May 22, 1951 v :5 sheets-sheet 3 IN VEN TOR.

Patented June 9, 1953 COMBINED SWITCH AND FASTENER John W. Liley,Ferndale, Mich., assignor of fiftyfve per cent to Michael J. Basso,Detroit, Mich.

Application May 22, 1951, Serial No. 227,640

(CI. 20G- 54) 27 Claims.

vThis invention relates to electrical switches, and more particularly toa, combined switch and fastener construction especially adapted for usein combination with the hinges of vehicle and other doors. Thisapplication is a continuationin-part of my applications Serial No.121,624, filed October 15, 1949, and Serial No. 164,159, filed May 5,1950.

In the past, switch constructions have been provided adapted to beactuated by the opening and closing of a closure means such as a door,for operating a lighting circuit or similar electrical circuit. In theconventional switch of this type, the switch unit must be mounted on thedoor frame by means of a separate opening in the frame, thus requiringthe additional labor and expense of forming this opening, as well as theprovision of fastener means for attaching the switch adjacent theopening.

, It is an object of the present invention to overcome the disadvantagesof the conventional door switch construction, and to provide a dooroperated switch which eliminates the necessity of forming an eXtraopening in the door frame, but which can be installed in the assemblysimultaneously with the attaching of the door hinges to the frame,without any additional labor being required.

It is a further object to provide a switch of the I above character,which is combined with a fastener used to attach the hinge to the doorframe, so that the switch operates through the fastener opening, andrequires no additional elements for securing the switch to the frame.

It is another object of the invention to provide an electrical switch ofthe above character, which is of the plunger type, and inwhichtheplunger is disposed' axially within .one of the hinge fasteners, wherebythe fastener serves the `dual purpose of supporting the door hinge bepulled through the door frame fastener opening and the hinge fasteneropening, and then attached tothe switch, the fastener thereafter beingapplied to the door frame in the usual man.- ner, without disturbingthis connection.

.It is a further object, in several forms of my invention, to provide aswitch of the above character, in which the fastener itself functions asone of the switch terminals, and in which the switch is capable ofclosing its contacts even though dirt or other foreign matter may be`present on the terminals.

It is also an object, in another form of the in extremely eflicientconstruction, and in which,

there are few moving parts to get out of order.

Other objects, features, and advantages of the present invention willbecome apparent from theA subsequent description, taken in conjunctionwith the accompanying drawings.

In the drawings:

Figure 1 is a side view, partly in cross-section, of a preferred form ofthe combined switch and fastener, wherein the fastener is utilized asone of the terminals of the switch;

Figure 2 is a side view, partly in cross-section, of the switch shown inFigure 1 installed in a, door frame and hinge, the switch being shownin.

its open position;

Figure 3 is a front view of the switch of Figures 1 and 2 showing thedisposition of the plunger within the fastener;

Figure 4 is a side view, partly in cross-section, of a modified form ofthe improved switch, hav-4 ing theplunger spring enclosed within theunit;

Figure 5 isa fragmentary cross-sectional view.V

of another modification of the switch, utilizing a plungerofnonconductive material;

Figure 6 is a side cross-sectional view of still another modication ofthe switch, for use with a two-wire circuit wherein two terminal setsare used;

Figure 7 is a cross-sectional view taken along the line 'l-l of Figure 6and showing the guide means for the contacts;

Figure 8 is a fifth embodiment of the invention,

similar in principle to that of Figure 6, but having a modified terminalconstruction; and.

Figure 9 is a cross-sectional view taken along the line 9-9 of Figure 8and showing the lateral configuration of the elements.

er used for attaching a door hinge to the door frame, so that the switchis operated by the opening and closing of the door. It will beunderstood however, that the principles of the invention are equallyapplicable to other types of fas- The invention is shown as applied to afasten-K'` teners, where it is desired to have a switch operated by anelement extending from one of the members secured by the fastener.

The invention comprises in general a fastener such as a screw or boltwhich is of essentially standard construction, this fastener beingcombined with and forming a part of a plungertype switch. The plunger isdisposed axially Within the fastener, the latter supporting the plungerfor axial movement therein. Resilient means are provided for normallyurging the plunger outwardly from the head of the fastener, thisresilient means being yieldable to allow a fastening tool to be appliedto the fastener when it is being assembled. The inner end ofthe-'plunger supports one or more switch terminals, these terminalsbeing movable axially with the plunger, so that the switch is closedwhen the plunger extends from the fastener, and is open when the plungeris partially or fully depressed. In its simplest form, the inventioncontemplates the use of the inner end of the fastener as one of theswitch terminals, although this need. not be the case. The mounting ofthe plunger within. the fastener, as well as the method of attachingthe: switch terminals to the inner end ofthe plunger, is such that thefastener may be rotated into its fastening position without turning theswitch terminals. or twisting the wires which are attached to suchterminals. The method. of attaching the terminal or terminals to theinner end of. the plunger is preferably such that relative lateralmovement or pivoting action is permitted between the. terminals, thusinsuring closure of the switch despite dirt. or other foreign matterwhich may accumulate on the contacts.`

lReferring more particularly to the drawings, Figures 1-3 illustrate aYpreferred embodiment of the invention in which the fastener, generallyindicated at ll, is shown as. a Phillips head screw of the type used inattaching vehicle doors, refrigerator doors and the like to theirrespective door frames. The screw Il has a shank portion i2 -providedwith an external thread I3, and a tapered head portion M having a socketl5 for receiving a Phillips head tool (not shown), and being adapted toengage a lock washer i6'. The screw il isessentially of standardmanufacture, but is preferably provided with a chamfered or taperedsurface Il at its inner end, and an axial bore i8.. The borey i8 extendsaxially from the socket l5, the inner end, of thebore being of smallerdiameter and provided withY a radial` shoulder i! so that thev end. ofthe, shank has a bearing portion il! for supporting and guiding theswitch plunger 22.

Plunger 22 is essentially of rod-like or cylindrical shape, and supportsthe. resilient spring 2,3, which is disposed aroundv its periphery andis utilized to normally urge the plunger outwardly fromthe. fastenerhead. Spring 23 engages at one end the shoulder i9 of the borev I8, andat its other end a head 2li which is formed at the outer end of theplunger 22- As is seen in Figure 1', the plunger may be of slightlytapered shape. so that a small clearance space 25 exists. between theplunger and the guide surface 2i when the plunger is extended. Thematerial of which` the plunger is made is not critical, although it ispreferably fabricated of metallic stock or other material havingsubstantial strength and durability.

The inner end 0f the plunger 22 supports a tubular member generallyindicated at 26, of'

conductive material, this tubular member vservtached.

ing as both a switch terminal and as connecting means for the insulatedwire conductor 21 which leads from the battery (not shown) or othersource of electrical power. For this purpose, a supporting membergenerally indicated at 28 is provided for securing member 26 to theinner end of the plunger, this supporting member being preferablyfabricated of a plastic orA otherl non-conductive material such asnylon. The inner end of plunger 22 is provided with a reduced portion 29having an annular gripping ring 3l integral therewith. The supportingmember 28 is provided with a recess 32 extending axially therein, andthe reduced portion 29 of the plunger is disposed within this recesssothat theV supporting member 2g abuts the shoulder 33 between reducedportion 29 of the plunger and the main portion of this plunger. Sincethe gripping ring 3l preferably has a forced fit with the supportingmember 23, the latter member is thus xedly secured to the inner end ofthe plunger.

The supporting member is provided with'an annular groove 35 whichextends around its otherwise cylindrical surface, this groove having.outwardly flared side Walls 35. The tubular member 26 has a mounting andcontact section 36 and a connector section 3l which is of somewhatsmaller diameter than the section 36. When the switch is assembled, thesection 36 is slipped axially over the supporting member 2B and ispreferably secured thereto by pressing section 36 inwardly adjacentgroove 35i, so that' a plurality of projections 38 are providedextending into this groove. It willbe observed that a slight clearancespace 3d is provided between the projections 38 and the bottom and sidewalls of groove 34. It will thus be seen that relative rotation betweenthe tubular member 2,6 and the supporting member 2.8 is permitted, andin particular that the tubular member may be held from rotating, forinstance by the attached wire 2l, while the supporting member 28 rotateswith the plunger and the fastener il while the fastener is being at- Itwill'be understood that other types of securing means could be providedbetween the tubular member 26. and the plunger 22 to allow relativerotation therebetween, without violating the principles of theinvention.

When in its assembled position the tubular member 2.6 extends pasttheshoulder33 so that it is free to engage the tapered surface Il of thefastener Il. For this purpose, the tubular member is provided with aflared contact flange 4l engageable with an intermediate portion ofthisv tapered` surface.

axial distance exists between the end 42 of the fastener and the endsurface 43 of supporting member 28. The contacts il' and 4| are thusassured of positive engagement, since the compression. in spring 23 willurge the plunger 22constantly outwardly.

The bared end of conductor 21 is preferably attached to the connectorsection 31 of the tubular member by means of crimping section 31, as

shown for example at 44. It will be understood however that othermethods of `attaching the conductor 2l to the tubular member coul'dbeused. It will beseen that when the conductor is secured to the tubularmember, a. continuouselectrical path will exist from the conductor tothecontact surface M. It will also be noted that the conductor iscompletely insulated from the plunger 22 since the supporting member 28,which is of It vwill be observed that, when flange 4l engages surfaceil, a substantial non-conductive material, prevents any contact of thesetwo elements. serve that due to the play 39 which exists between thetubular member and the supporting member, it is possible for the contactsurface 4I to engage a portion of the contact surface I1, while dirt orother foreign matter prevents engagement of other portions of thesesurfaces. This is because the tubular element is allowed a pivotingaction around the supporting member 28 without disengaging projections38 and groove 34.

The application of the combined switch and fastener to a door hinge isshown in Figure 2. In this illustration, one leaf 45 of the hinge isshown as being secured to the door frame 46, the fastener II .beingthreadably engaged with an internallyr threaded member 41 such as a nutwhich is welded or otherwise secured to the inside of the frame. Inassembling the switch and fastener in this manner, the wire 21 is firstpassed through the nut 41 and the openings in frame 46 and hinge leaf45. rIhe bare end of the wire 21 is then crimped within the section 31of tubular member 26. The hinge and frame holes are then aligned, andthe wire and tubular member pushed back through these holes. It will beobserved that the tubular member will pass freely through the nut 41,since its diameter is substantially less than that of thread I3. Thethreads of the screw I I are then engaged with nut 41, and the screw isdriven to its full home position by means of a wrench or other tool.

It is a principle of the invention that the tool for driving thefastener may 'be applied Without interference from the switch portion ofthe device, and without disturbing the switch portion in any way. Theoperation of this principle will be obvious from the foregoingdiscussion, since it will be seen that when the tool is applied tosocket I5, it will depress plunger 22 by contact with its head 24,compressing spring 23, so that the plunger will be retracted within boreI8 of the fastener. This position is shown in dot-dash lines in Figure2, and it will be seen from this figure and from Figure 3 that theplunger is capable of full retraction so that the tool may fully enterthe socket I5. When this action occurs, the contacts I1 and 4I will ofcourse be separated. As the fastener is rotatably driven, frictionbetween the fastener and plunger, especially through the intermediary ofthe spring 23, will cause rotation of the plunger as well as ofsupporting member 28. Since, as described previously, denite play 39exists between the supporting member 28 and tubular member 26, thetubular member will not be forced to rotate with the supporting member.'This will prevent unwanted twisting of the wire 21 within thedoor frame.When the fastener has been driven fully home, removal of the tool willcause immediate projection of plunger 22, and the contacts I1 and 4Iwill thereafter be normally engaged. Since fastener II is grounded tothe frame, a lighting or other circuit will be completed by the contact.

In operation, with the door (not shown) normally closed, the hinge leaf48 attached to the door will engage the head 24 of the plunger, thusretracting the plunger and separating the contact surfaces I1 and 4I toopen the electrical circuit. Upon opening of the door, the hinge leaf 48will leave head 24, allowing spring 23 to project the plunger, closingthe contact. The wire 21 will of course be supported so that it may moveback and forth with the tubular member 26. It will be observed that allthe switch parts are en- It is also important to obtrely enclosed withinthe door frame, thus preventing the accumulation of dirt or otherforeign matter on the contact surfaces. Should dirt accumulate howeveron the contact surfaces, the pivoting action described previously willinsure engagement of the contacts on at least a portion thereof.Relative radial movement between the contact surfaces I1 and 4I willalso be permitted because of the clearance space 25 existing between theplunger 22 and the fastener I I. Should it be desired to repair orreplace the switch, it is merely necessary to remove the screw II fromthe hinge and withdraw the switch through the apertures in the nut,frame and hinge. Since the ordinary hinge will be provided with aplurality of attaching screws, the replacement of the switch may thusIbe effected without in any way disturbing the mounting of the door onthe frame.

Figure 4 illustrates a second embodiment of the invention which issimilar in principle to that of Figures 1-3, but wherein the plungerspring 49 is enclosed within a tubular member 5I of conductive materialwhich is secured as an extension to the reduced end 52 of fastener 53.Inthis embodiment, the fastener is provided with an axial bore 54extending entirely therethrough, this bore being of substantially thesame diameter as the plunger 55, so that the plunger is slidably mountedtherein. The tubular member 5I, which is in effect an extension of thefastener and which acts as a spring housing and as a contact for theswitch, is provided with a plurality of inwardly extending tabs 56 whichsecure the end 51 of the spring 49 against axial movement. The oppositeend 58 of the spring is of reduced diameter, and engages a reducedportion 59 of the plunger 55, the shoulder 6I on the plunger preventingmovement of this end of the spring. The spring is preferably of thetension type so that the plunger will be normally urged outwardly fromthe head 62 of the fastener. The inner end of the plunger 55 is providedwith a further reduced portion 63 to which is xedly secured a supportingmember 64 of nonconductive material, similar to the supporting member 28of the previous embodiment. Member 64 is preferably provided withoppositely disposed tapered surfaces 65 and 66, a cylindrical portion 61extending from portion 65 against spring end 58.

The unit is provided with a combined wire connecting element and contactgenerally indicated at 68, which is analogous to tubular member 26 ofthe previous embodiment. This element comprises a wire connector section69 within which the bare end of the wire 1I is inserted and secured, anda socket section 12 having a plurality of axially extending springfingers 13 which grip the supporting member 64. These spring ngers haveinwardly inclined portions 14 which may be initially forced over theflared surface 6G of the supporting member 64, and thereafter engage theflared surface 65 on the opposite side of this supporting member. Theengagement of the spring fingers with supporting member 64 is preferablysuch that relative rotation between these parts is permitted, so that,as in the previous embodiment, the fastener may be driven home withouttwisting of the wire 1I. f

When the plunger 55 of the embodiment of Figure 4 is permitted to moveinto its extended position, the inwardly inclined portions 14 of thefingers 13 will engage the annular end surface 15 of tubular member 5I,thus completing a circuit between the wire 1I and the fastener 53. Itwill be observed that, as in the previous embodiment, the springviingers 13 are completely insulated from the plungertlil, and thus fromthe fastener, except when the contacts are closed. Likewise, as in theprevious embodiment, relative lateral movement will be permitted betweenthe spring finger contacts and thesurface 15, by virtue of the play i6existing between the spring fingers and the supporting member e9.

Figure shows a third embodiment of the invention which .is generallysimilar in principle to that of the previous embodiment but wherein theplunger 11 is fabricated of nonconductive material such as plastic,rather than of conductive material. A contact element 1e of conductivematerial is rotatably secured to the reduced end 19 of plunger 11.Spring 8i normally urges this contact element into engagement with theend 92 oftubular extension member 33, the angular contact surface 8d ofelement 18 insuring mutual contact of the elements. The wire 85 issecured within the connector portion S5 of contact member `153. It will.be observed that in this construction'the supporting member, such asmember @il in Figure 4, is eliminated, since the nonconductive nature ofthe plunger 11 makes the supporting member unnecessary. Figures 6 to 9illustrate two more modifications of the invention which are generallyimilar in principle to the previous modifications, but Which areespecially adapted for use in two-wire systems which do not use thegrounded fastener as part of the circuit. In Figures 6 and 7 thefastener 81 is provided with an extension member S3 of annular shapewhich is rotatably secured to the reduced end 99 of the fastener bymeans of a snap ring 9|. This extension member is fabricated ofinsulative material and has embedded in its `walls a pair of conductors92 and 93 having Contact ends Si@ and 95 respectively projectinginwardly into the space 95 within the extension member. Space 9b ispreferably of noncircular cross-section, and a contact nut 91 secured tothe reduced end 93 of the plunger 99 'is slidably housed within thisspace. A compression spring |01 is held between contact nut 91 and aplug |92 at the end of extension 88, this spring normally urging thecontact nut into engagement with contacts 94 and 9b. The opposite endsof conductors 92 and 93 extend outwardly from extension 38 and areprovided with male terminals |03 and Hill respectively, these terminalsbeing adapted to be engaged by a receptacle l5 attached to the end ofthe two-wire cable Hit. The other end of plunger 99 may be provided withan enlarged head |91 movable within a counterbore |98 in the fastener81. In assembling the unit shown in Figures 6 and '7, the spring ||l|and contact unit 91 will be placed within the tubular` housing 38, andthis housing then mounted on the end of the fastener by means of snapring 9 l The plunger may then be threadably engaged with contact nut 91,the rotation of the nut being prevented because of the noncircular shapeof the nut. It will be observed that a driving rotation of fastener 81will not cause twisting of wire cable i6, since the snap ring 9| permitsrelative rotation between the fastener and housing 88. In operation,spring lili will normally urge contact nut 91 into bridging engagementWith contacts 9e and 95, plunger 99 being held in projected position,and depression of the plunger will move the contact nut to interruptthis bridging contact.

Figures 8 and 9 illustrate another embodiment of the two-wire type ofswitch similar in principle to that of Figures 6 and '7, but Whichutilizes a metallic switch housing lili? in Place of the nonconductivehousing E3 of the previous embodiment. The extension |99 is provided onits outer surface with a pair of oppositely disposed elongated recessesHl and H2, within which are disposed conduotors i i3 and H4respectively. These conductors are preferably insulated by dipping themin rubber or coating them with a plastic varnish or the like, and haveinwardly extending contact ends ||5 and H6 which project throughapertures lli' and H9 respectively in the extension |99. The contactends H and H are adapted to be bridged by a U-shaped bridging member |9embedded in a block |2i of insulated material. Block |2| is slidablydisposed within housing |99 and is secured to the reduced end |22 of theplunger, in this case by a bayonet slot |23. The block is normally urgedtoward the contact ends H5 and Ht by spring |29, so that the ends of thebridging member engage the contact ends.

'A plug |25, heldin place by a pin |25, holds spring 24 within member99. The outer end of condoctors H3 and lid; may be provided, as in theprevious embodiment, with male terminals |21 and 28 respectively. Aplastic or other insulating sleeve |29 may be positioned over housing|09 to further insulate the conductors and to protect the switchhousing.

While it will be apparent that the preferred embodiments of theinvention herein disclosed are Wellcalculated to fulfill the objectsabove stated, it lwill be appreciated that the invention is susceptibleto modification, Variation and change without departing from the properscope or fair ,l meaning of the subjoined claims.

What is claimed is:

l. In combination, a rotatably applied fastener having a shank portion,a plunger within said shank portion, the head of said plunger beingmovable between a position extending outwardly from said shank portionand a position retracted within said shankportion, an electrical contactmovable by said'plunger during movement of the latter between its saidpositions, and a second electrical contact engageable by said firstContact during said movement, the two contacts being in engagement whenthe plunger is in one of its said positions and in spaced relation whenthe plunger is in its other position.

2. In combination, a fastener having a shank portion and a head portion,the head portion being adapted to be engaged by a tool for applying saidfastener, a plunger within said fastener, the head of said plunger beingmovable between an extended position projecting outwardly of said headportion and a retracted position within said shank `portion and .out ofobstructing relation with said tool, and electrical conductor connectingmeans carried by said plunger, said connecting means being rotatablewith respect to the plunger.

3. In combination, a rotatably applied fastener. a plunger within saidfastener, the head of said plunger being movable between a positionextending from said fastener an-d a position retraoted within saidfastener, electrical contact means .actuatable by saidv plunger duringits movement between said positions, and electric conductor connectingmeans carried by said plunger, said connecting means being rotatablewith respect to said plunger.

4. In combination, a. rotatable fastener, a plunger within saidfastener, the head of said plunger being movable between a positionprojecting from said fastener and a position retracted within saidfastener, electrical contact means actuatable by said plunger intoclosed position ywhen the plunger moves into its extended position, andresilient means urging the fastener into its extended position. Y

5. In combination, a rotatable fastener having a shank portion and ahead portion adapted to be engaged by a rotating tool, a plunger withinsaid fastener, the head of said plunger being movable between a positionextending from said head portion and a portion retracted within saidshank position, resilient means for urging said plunger toward itsextended position, electrical contact means adapted to be actuated bysaid plunger, and electrical conductor connecting means carried by saidplunger, said connecting means being rotatably mounted with respect tosaid plunger, whereby the fastener may be rotated Without rotating saidconnecting means.

6. In combination, a rotatably applied fastener, a plunger movableWithin said fastener, an electrical contact movable by said plunger, anda second electrical Contact engageable by said first contact during saidmovement, said contacts being in engagement when the plunger is in oneposition and in spaced relation when the plunger is away from saidposition.

7. In combination, a rotatably applied fastener, an actuating elementmovable Within said fastener, an electrical contact actuatable by saidelement during its movement, said contact being engageable with saidfastener when the element is in one position, and electrical conductorconnecting means supported by said fastener, said connecting means beingmounted for rotational movement with respect to the fastener.

8. In combination, a fastener, a plunger movable within said fastener,electrical contact means actuatable by said plunger during its movement,said Contact means being engageable with an end surface of said fastenerin one position of the plunger, resilient means for urging the plungerinto said position, and electrical conductor connecting means supported'by said plunger, said connecting means being mountedv for rotationalmovement with respect to said plunger.

9. In combination, a fastener, a plunger movable within said fastener',resilient means urging said plunger toward one end of said fastener,electrical contact means carried by said plunger and insulatedtherefrom, second electrical oontact means engageable with said firstcontact means when said plunger is moved toward said one end of thefastener, an-d electrical conductor connecting means connected to saidfirst contact means, said connecting means being rotatable with respectto said plunger.

l0. In combination, a fastener, a plunger movable within said fastener,resilient means for urging said plunger toward one end of said fastener,an insulating member carried by one end of said plunger', electricalcontact means rotatably mounted on said insulating member, secondelectrical contact means engageable by said first contact means when theplunger is moved toward said one end of the fastener, and electricalconductor connecting means connected to said rst contact means, wherebysaid connecting means is also rotatable with respect to said insulatingmember.

11. The combination according to claim 10, said first contact meansbeing supported for limited pivotal movement with respect to saidinsulating member, whereby said rst and second contact means may bemutually engaged at only a portion of their respective surfaces.

12. In combination, a fastener, a plunger movable within said fastener,resilient ymeans for urging the plunger toward one en-d of the fastener,altubular member mounted on said plunger and having a contact portionconductively engageable with said fastener when the plunger is urgedtoward said one end of the fastener, an electrical conductor connectingportion on said tubular member, and means for supporting said .tubularmember for rotational movement with respect to said plunger.

13. In combination, a fastener, a plunger movably mounted Within saidfastener, resilient means disposed within said fastener and urging saidplunger toward one end of the fastener, an insulating member secured toone end of the plunger, a tubular member supported for rotational andlimited pivotal movement on said insulating member, and a contactportion on said tubular member and engageable with the other end of saidfastener when the plunger is urged toward said one end of the fastener.

14. In combination, an externally threaded fastener, an axial borewithin said fastener and having a shoulder therein, a plunger withinsaid fastener, resilient means disposed within said bore andengageableWith said shoulder and one end of the plunger to urge the plunger into aposition projecting fromone end of said fastener, an insulating membersecured to the other end of said plunger, an electrically conductivemember rotatably mounted on said insulating Vmember and having a contactportion conductively engageable with the 'other end of said fastenerwhen the plunger is insaid projected position, and electrical conductorconnecting means on said conductive member.

15. The combination according to claim 14, said fastener being furtherprovided with a toolreceiving recess, lsaid plunger being movable to aretracted position within ysaid axial bore by the application ofatooltozsaid recess.

16. In combination, a fastener having an extension thereon, a plungermovable Within Said fastener, resilient means Within said extension forurging said plunger toward one end of said fastener, electrical contactmeans carried by said plunger and conductively engageable with saidextension When the plunger is moved toward said one end of the fastener,and electrical conductor connecting means connected to said contactmeans.

17. In combination, a fastener having an extension thereon, a plungermovable Within said fastener, resilient means within said extension forurging the plunger toward one end of said fastener, an insulating membersecured to one end of said plunger, and electrical contact meanscomprising a plurality of ngers mounted on said insulating member andengageable with said extension when the plunger is moved toward said oneend of the fastener, said fingers being supported for rotationalmovement with respect to said insulating member.

18. In combination, a fastener having an eX- tension of conductivematerial, a plunger of insulative material movable Within said fastener,electrical contact means rotatably secured to one end of said plungerand engageable with said extension when the plunger is moved toward oneend of said fastener, and means for connecting an electrical conductorto said contact means.

amnesia 1-9. In combination, a fastener having a hollow extensionrotatably secured thereto, a pair of spaced electrical conductorssupported by said extension and having contacts extending into the spacewithin said extension, an actuating element movable within saidfastener, an electrical bridging member within said extension andsecured to one end of said element, and resilient means for urging saidbridging member into engagement with said contacts.

20. In combination, a guide member having an extension rotatably mountedthereon, a pair of electrical conductors supported by said extension, apair of contacts extending inwardly from said conductors, a yplungermovably mounted .in said guide member and having a portion extendingwithin said extension, a contact bridging member movably disposed withinsaid extension and secured to said plunger portion, said bridging memberbeing of .non-circular shape whereby the bridging member isnon-rotatably supported by said extension, and resilient means .forurging said bridging member rinto engagement with said contacts.

211. The combination according to claim 20, said extension being ofinsulative material, said conductors being embedded in spaced relationwithin said extension wall.

2-2. The combination according to claim 20, said extension havingaxially extending depressions along its peripheral surface, saidconductors being disposed within said depressions, and radial aperturesin said extension, the ends of said conductors extending through saidapertures to Aform said contacts.

23. The combination according to claim 20, said conductors vextendingbeyond the end of said extension and being adapted to be connected to atwo-Wire receptacle.

24. A device of `the character described comprising -in combination, anexternally threaded member having a flared and recessed head and adaptedto engage Aan opening in ra door hinge, a bore in saidY member, -a.plunger .longer than 12 said member and slidable in said bore, a switchhousing mounted for rotation at one end of said threaded member,electric conductors carried by said housing and arranged to be contactedby a conductive nut carried at one end of said plunger.

25. In combination, a screw having a longitudinal bore therein, aplunger slidable in said bore, said plunger having a contact nut at oneend thereof, a switch housing mounted for rotation on the small end of isaid screw and arranged 'to enclose one end of said plunger and saidnut, electrical conductors entering said housing and having terminalsarranged to be contacted by said nut, means to urge said nut intocontacting relation with said terminals and means to limit the movementof said nut away from said terminals.

26. In a device of the character described, including a hinge, athreaded hollow stud having a iiared and recessed head and arranged tosecure one leaf of said hinge to an automobile frame, a plunger slidablein said hollow stud and having an end arranged to be contacted by theother leaf of said hinge, a contact nut threaded onto the other end ofsaid plunger, a switch housing mounted fo'r rotation on the reduced endof said stud, electric conductors carried by said housing andterminating at one end `in elements adapted to be contacted by said nutand terminating at the other end in male terminals extending beyond theend of said housing.

27. The structure of claim 26, including means in said housing for,preventing the rotation of said nut.

JOHN W. LILEY.

References Cited in the iile of this patent UNITED STATES PATENTS NumberName Date 1,483,399 Whittington Feb. 12, 1924 1,529,429 Gross Mar. 10,1925 1,622,541 Raley et al Mar. 29, 1927

